Treatment of coke



Patented July 31, 1934 TREATMENT OF COKE Alfred R. Powell, Mount Lebanon Township, Allegheny County, Pa., assignor to The Koppers Company of Delaware, a corporation of Delaware Serial No. 560,653 r 3 Claims.

" 6- adhesive form and then applying them eith t certain lumps of coke for mixture with a mass or indiscriminately to practically all of the lumps of coke. The process whereby coke has been rendered dustless has, in most cases, been accomplished by means of a separate operation.

The present invention is an improvement over existing methods of treatment of coke whereby it may be easily and efiiciently provided with distinctive markings and, at the same time, ren- 6 i dered substantially dustless.

In the treatment of coke in accordance with my invention, I preferably employ two solutions containing compounds which, when combined, will form a precipitate on the surfaces of the 1 lumps of coke that will be of such nature as to render the coke distinctive and thereby indicate its origin and its quality. By way of example, such solutions may consist of calcium nitrate, Ca(NO3)2, and copper sulphate, CuSOr. When "i these chemicals are combined, the following reaction takes place:

Ca(NO3) 2+CuSO4=Cu(NO3) z+CaSO4.

In treating coke with the foregoing solutions,

the clear solutions containing the respective reagents are preferably stored in separate tanks and the solutions may be mixed just prior to being sprayed on the coke. The reaction is completed in about five seconds which is suificient i to permit the mixing of the solutions and the spraying of the mixed liquid on the coke before the white precipitate of calcium sulphate is formed.

The precipitate thus formed is in spots or speckles and these white spots or dots are very distinct on the dark background of the surfaces of the lumps of coke. Inasmuch as the precipitate is formed on the cellular surface of the coke,

it adheres thereto very closely and forms a peras are necessary to eiiect complete reaction between them.

In case, however, it is desired to render the coke substantially dustless by providing a film or hygroscopic material thereon, the proportions of-the chemicals referred to above may be varied. I v

If an excess of calcium nitrate is employed, the solution remaining after the reaction has taken place will contain both calcium nitrate and copper nitrate, which constitutes a highly efficient hygroscopic solution for the purpose desired. The precipitate of calcium sulphate will be formed as in the previous case, but the excess calcium nitrate will be left in solution with the copper nitrate produced by the reaction. Since the mixture of the two solutions is sprayed on the coke, this remaining hygroscopic solution will tend to keep the coke dustless even in a dry atmosphere.

If, instead of white spots or speckles, it is desired to produce similar marks of another color, water-soluble dye or other suitable dye of de sired color may be added to one of the solutions in such quantity that the precipitated calcium sulphate will produce colored spots on the coke instead of white spots that result from uncolored solutions.

For example, malachite green may be added to one of the solutions and. the resulting precipitate of calcium sulphate is of green color. Also, a green color may be obtained by substituting calcium chloride for calcium nitrate. The spots of precipitate resulting from this reaction are of olive green color.

The treatment described above may occur at any time after the coke is manufactured but it is preferable that it occur just before the coke is shipped or delivered to customers in order that a minimum amount of handling may occur after the coke is sprayed to mark it or to render it dustless. It has been found by experience that the spraying of the coke is most conveniently done as the coke falls from a conveyor into a railroad car, truck or other conveyance just before leaving the plant.

While diiierent amounts of the respective solutions may be employed, as desired, I have found that suitable amounts are four pounds of Ca NOa)z-lI-Iz0 per gallon of solution, to which may be added a sufficient quantity of suitable water-soluble dye. The other solution is a water solution containing one pound of CuSO4-5I-I2O per gallon.

In applying the solutions, each are delivered to the sprays at the rate of one gallon of each solution per ton of coke treated or a total of two gallons of each solution per ton of coke.

UN TED, TATES, PATENT-lorries The result of this treatment is to leave on the surfaces of the coke, the following quantities of salts per ton of coke:

3.05 lb Ca,(NO3)2-4H2O 1.18 llC! C1 1(NO3)2-5H2O 0.68 lb"; CaSQ4-2H2O The total quantity of hygroscopic salts is,

therefore, 4.23 pounds per ton of coke and large scale operations have indicated this amount as being sufiicient to make coke substantiallyis the equal, if not the superior, of calcium chlo ride which has been extensively used for this purpose. It is thus insured that the coke Will remain substantially dustless regardless of atmospheric conditions. 1

The presence of a copper compound causes the coke to burn with a green flame which renders it distinctive and also may be used to indicate the origin or the quality of the coke. The coking surfaces are marked with spots or speckles of any desired color and .it is unnecessary to provide a solution in which solid material is maintained in suspension before it is sprayed on thecoke. This distinctive appearance is, as well known, very desirable for marking the coke for the reasons stated above.

The foregoing and other advantages will be apparent to those skilled in the art of treating coke.

I claim as my invention:

1. The process of treating coke, which comprises applying thereto solutions of calcium nitrate and copper sulphate.

2. The process of treating coke, which comprises applying thereto solutions of calcium nitr e d pp r. ulphata; the calcium nitrat being in excess of that required toreaot with thecopper sulphate.

3. The process of treating coke,.WhiQh:1Qom,-i 

